Imperial Roman Church

The Imperial Roman Church was the state church of the Roman Empire, existing from 380 AD to 741 AD. The church was established by Theodosius I's Edict of Thessalonica, which made Christianity the empire's state religion; however, the forefather of the church's creation was Constantine the Great, who converted to Christianity before the Battle of Milvian Bridge in 312 AD, and who legalized the faith across the empire, convincing much of Rome's nobility to convert as well. Constantine granted the Lateran to Pope Militiades, and Constantine allowed for the subjects of the empire to enjoy full religious freedom for the first time. However, Theodosius' edict in 380 AD implemented Christianity as the state religion and persecuted the pagan faiths, allowing for Christian mobs to destroy pagan temples, sacred sites, and artwork. The Christians also committed acts of violence against each other due to disagreements over theological concepts, and it was even said that more Christians killed each other in the century after Christianity was legalized than had suffered martyrdom under the Romans over the course of almost 300 years of intermittent persecution.

The Emperor played a large role in the Imperial Roman Church, creating dioceses as administrative units and appointing a bishop for every province. The church was divided into two major factions: the Latin Rite in the Western Roman Empire and the Greek Rite in the Eastern Roman Empire. The Latin Rite, centered around Rome, used Latin as its liturgical language and recognized the Pope (the Bishop of Rome) as the head of its church (the Catholic Church), while the Greek Rite in Constantinople used Greek as its liturgical language and refused to recognize the primacy of the Pope over the other bishops (with the Ecumenical Patriarch of Constantinople being the de facto head of the Eastern Orthodox Church). In 476, the Western Roman Empire was destroyed by invading Germanic tribes, but the Papacy survived under barbarian rule. The Imperial Roman Church survived in the Byzantine Empire as the Orthodox Church, and, in 535, the Byzantines invaded Italy and overthrew the Ostrogothic Kingdom, dominating the Papacy once again. The Popes were dominated by the Byzantine Exarchate of Ravenna, and the Popes were loyal to the Byzantine emperor as their political lord during the Byzantine reconquest period. However, Pope Gregory III died in 741, and he was the last Bishop of Rome to ask the Byzantine ruler to ratify his election. With Gregory's death, the Imperial Roman Church was no longer subservient to the Roman emperors, and the former Roman church split between Roman Catholicism and Greek Orthodoxy.